Japanese Patent Application Publication No. 2005-227141 (JP-A-2005-227141) relates to a vehicle diagnosis system that diagnoses degradation of a consumable item of a vehicle, and displays results of the diagnosis in a vehicle-mounted display screen. This system factors in information about a driver's driving behavior, and displays the degree of degradation of the consumable item and the driving behavior in an associated fashion.
In recent years, taking into consideration environmental issues such as global warming and the like, the development of vehicles equipped with a battery as a motive power source, such as electric motor vehicles, hybrid motor vehicles, etc., is being vigorously pursued.
Such a vehicle is equipped with a battery as a motive power source of an electric motor that drives the vehicle. Generally, such a battery is a secondary battery capable of being charged and discharged. In the case of an electric motor vehicle, the battery is charged by using a charging cable. In the case of a hybrid motor vehicle, the engine turns a vehicle-mounted generator to generate electric power, and the thus-generated electric power is used to charge the battery. In both the electric motor vehicle and the hybrid motor vehicle, when the vehicle is decelerated, regenerative braking is performed in a driving motor, and electric power generated at the time of regenerative braking is also charged into the battery.
Thus, the battery mounted in a vehicle as a motive power source degrades with the time of use, and therefore has a certain length of service life. As the battery is used for long time, the internal resistance of the battery rises, and the charging-discharging capability of the cell (battery capacity) gradually decreases. This time-dependent degradation of the battery varies depending on the driving pattern of the driver, the environment of the vehicle in which the battery is mounted.
Therefore, there is a possibility that the service life of the battery can be prolonged by optimizing the control regarding the charging and discharging of the battery, separately for each vehicle.
The battery, too, is a consumable item, and it is conceivable to apply thereto the foregoing vehicle diagnosis system disclosed in Japanese Patent Application Publication No. 2005-227141 (JP-A-2005-227141). However, in the foregoing system, it is not easy to understand what a user need to do after a vehicle diagnosis, and what betterment measures are available. It is desirable to present users what measures for increasing the battery's service life are available.